CompTIA glossary
Key CompTIA certification terms and acronyms.
Definitions are AI-assisted and reviewed for general accuracy — verify critical details against CompTIA's official documentation.
802.11
A family of IEEE wireless networking standards defining Wi-Fi communication protocols, with variants such as 802.11a/b/g/n/ac/ax.
802.11
A family of IEEE standards defining wireless LAN communication protocols, with amendments (a/b/g/n/ac/ax) specifying different frequencies, speeds, and features.
ACLAccess Control List
A set of rules applied to a router or firewall interface that permits or denies traffic based on defined criteria such as source IP, destination IP, or port.
AESAdvanced Encryption Standard
A symmetric block cipher adopted by NIST, supporting 128-, 192-, and 256-bit key lengths, widely used for data encryption.
APIPAAutomatic Private IP Addressing
A feature that allows a host to self-assign an IP address in the 169.254.0.0/16 range when no DHCP server is reachable.
APTAdvanced Persistent Threat
A prolonged, targeted cyberattack in which an adversary gains and maintains unauthorized access to a network, often for espionage or data theft.
Attack Surface
The total set of points on a system or network where an unauthorized user could attempt to enter or extract data.
BCPBusiness Continuity Plan
A documented strategy that enables an organization to maintain or quickly resume critical business functions during and after a disruptive event.
BGPBorder Gateway Protocol
A path-vector exterior gateway protocol used to exchange routing information between autonomous systems on the internet.
BIOSBasic Input/Output System
Legacy firmware stored on a motherboard chip that initializes hardware and loads the bootloader during startup.
Chain of Custody
Documentation that tracks the collection, transfer, and handling of digital evidence to ensure its integrity for legal proceedings.
CIA Triad
A foundational security model representing Confidentiality, Integrity, and Availability as the three core objectives of information security.
CIDRClassless Inter-Domain Routing
An IP addressing scheme that replaces classful addressing by using variable-length subnet masks to allocate IP addresses more efficiently.
CPUCentral Processing Unit
The primary component of a computer that executes instructions and performs calculations for the operating system and applications.
CVECommon Vulnerabilities and Exposures
A publicly maintained dictionary of disclosed cybersecurity vulnerabilities, each assigned a unique identifier for standardized reference.
CVECommon Vulnerabilities and Exposures
A standardized identifier and public list of known cybersecurity vulnerabilities maintained by MITRE.
CVSSCommon Vulnerability Scoring System
An open framework that produces a numerical score (0–10) representing the severity of a software vulnerability.
CVSSCommon Vulnerability Scoring System
An open framework that produces a numeric score from 0 to 10 representing the severity of a software vulnerability.
DACDiscretionary Access Control
An access control model where resource owners define and assign permissions to other users at their own discretion.
DHCPDynamic Host Configuration Protocol
A network service that automatically assigns IP addresses and other configuration parameters to clients using a four-step DORA process.
DHCPDynamic Host Configuration Protocol
A network protocol that automatically assigns IP addresses and network configuration parameters to client devices.
Diamond Model
An intrusion analysis framework that models cyber events using four core features: adversary, capability, infrastructure, and victim.
DisplayPort
A digital display interface standard capable of carrying video, audio, and data; commonly found on computers and monitors.
DLPData Loss Prevention
A set of tools and policies designed to detect and prevent unauthorized transfer or exfiltration of sensitive data.
DLPData Loss Prevention
A set of tools and policies designed to detect and prevent unauthorized transmission or exposure of sensitive data.
DNSDomain Name System
A hierarchical naming system that resolves human-readable domain names into IP addresses.
DNSDomain Name System
A hierarchical, distributed naming system that resolves human-readable domain names to IP addresses.
EDREndpoint Detection and Response
A security solution that continuously monitors endpoints for suspicious activity and provides detection, investigation, and response capabilities.
EDREndpoint Detection and Response
A security solution that continuously monitors endpoints for suspicious activity, records telemetry, and enables rapid investigation and remediation.
ESDElectrostatic Discharge
A sudden transfer of static electricity between objects that can permanently damage sensitive electronic components.
False Positive
An alert generated by a security tool that incorrectly identifies benign activity as malicious.
GPUGraphics Processing Unit
A processor specialized for rendering images and video; can be integrated into the CPU or installed as a discrete card.
HDDHard Disk Drive
A mechanical storage device that reads and writes data on spinning magnetic platters using read/write heads.
HDMIHigh-Definition Multimedia Interface
A digital audio/video interface standard for transmitting uncompressed video and audio from a source to a display.
IDSIntrusion Detection System
A system that monitors network or host activity for malicious behavior and generates alerts without blocking traffic.
IDSIntrusion Detection System
A system that monitors network or host activity for malicious behavior and generates alerts without actively blocking traffic.
IOCIndicator of Compromise
Observable artifacts such as IP addresses, file hashes, or domain names that suggest a system may have been breached.
IPSIntrusion Prevention System
A system that monitors traffic for malicious activity and can actively block or drop offending packets in real time.
IPSIntrusion Prevention System
A security system that monitors network traffic and actively blocks or drops malicious packets in real time.
IRIncident Response
A structured process for detecting, containing, eradicating, and recovering from security incidents while preserving evidence.
Kill Chain
A model describing the sequential stages of a cyberattack, from reconnaissance through actions on objectives, used to identify defensive opportunities.
LACPLink Aggregation Control Protocol
An IEEE 802.3ad protocol that dynamically negotiates the bundling of multiple physical links into a single logical channel for increased bandwidth and redundancy.
M.2
A compact form-factor expansion slot on motherboards that supports SATA or NVMe SSDs and other small modules.
MACMandatory Access Control
An access control model where the OS enforces access based on classification labels assigned to subjects and objects by a central authority.
MFAMulti-Factor Authentication
An authentication method requiring two or more verification factors from different categories: something you know, have, or are.
MITRE ATT&CK
A publicly available knowledge base of adversary tactics and techniques based on real-world observations of cyberattacks.
MPLSMultiprotocol Label Switching
A routing technique that directs data from one node to the next based on short path labels rather than long network addresses.
MTUMaximum Transmission Unit
The largest size, in bytes, of a packet or frame that can be transmitted over a network segment without fragmentation.
NATNetwork Address Translation
A process that remaps one IP address space to another by modifying IP header information, commonly used to allow private hosts to access the internet.
NIST CSFNational Institute of Standards and Technology Cybersecurity Framework
A voluntary framework providing organizations with standards and best practices to manage and reduce cybersecurity risk.
NTPNetwork Time Protocol
An application-layer protocol used to synchronize clocks of networked devices to a reference time source with millisecond accuracy.
NVMeNon-Volatile Memory Express
A storage protocol designed for SSDs that uses the PCIe bus to deliver significantly higher throughput than SATA.
OSIOpen Systems Interconnection
A seven-layer conceptual framework (Physical, Data Link, Network, Transport, Session, Presentation, Application) used to describe how network protocols communicate.
OSPFOpen Shortest Path First
A link-state interior gateway routing protocol that uses Dijkstra's algorithm to calculate the shortest path to each destination.
PCIePeripheral Component Interconnect Express
A high-speed serial expansion bus standard used to connect GPUs, SSDs, and other add-in cards to the motherboard.
Penetration Testing
An authorized simulated attack against systems or networks to identify exploitable vulnerabilities before malicious actors do.
Phishing
A social engineering attack that uses deceptive emails or messages to trick recipients into revealing credentials or installing malware.
PKIPublic Key Infrastructure
A framework of policies, hardware, software, and procedures used to create, manage, distribute, and revoke digital certificates.
PoEPower over Ethernet
A technology defined in IEEE 802.3af/at/bt that delivers electrical power along with data over standard Ethernet cabling to connected devices.
POSTPower-On Self-Test
A firmware-level diagnostic routine that runs when a computer is powered on to verify hardware components are functioning correctly.
Power Supply
A component that converts AC mains electricity to regulated DC voltages (typically 3.3V, 5V, 12V) required by computer components.
QoSQuality of Service
A set of techniques used to manage network traffic by prioritizing certain data types to meet performance requirements.
RADIUSRemote Authentication Dial-In User Service
A networking protocol that provides centralized authentication, authorization, and accounting (AAA) for users connecting to a network.
RAIDRedundant Array of Independent Disks
A storage technology that combines multiple drives for redundancy, performance, or both, using configurations such as RAID 0, 1, 5, and 10.
RAMRandom Access Memory
Volatile memory that temporarily stores data and instructions currently being used by the CPU.
RBACRole-Based Access Control
An access control model where permissions are assigned to roles, and users are granted access by being assigned to appropriate roles.
Risk Appetite
The level and type of risk an organization is willing to accept in pursuit of its objectives.
RSARivest–Shamir–Adleman
An asymmetric encryption algorithm that uses a mathematically linked public/private key pair for encryption and digital signatures.
SATASerial Advanced Technology Attachment
An interface standard used to connect storage devices such as HDDs and SSDs to a motherboard, with a maximum speed of 6 Gb/s.
SIEMSecurity Information and Event Management
A platform that aggregates, correlates, and analyzes log and event data from multiple sources to detect security incidents.
SIEMSecurity Information and Event Management
A system that aggregates and correlates log data from multiple sources to detect and alert on security events in real time.
SNMPSimple Network Management Protocol
An application-layer protocol used to collect and organize information about managed devices on IP networks and modify device behavior.
SOARSecurity Orchestration, Automation, and Response
A platform that automates security workflows and coordinates responses across multiple tools to reduce manual analyst effort.
SOARSecurity Orchestration, Automation, and Response
A platform that automates security workflows, integrates tools, and coordinates incident response actions to reduce manual effort.
SSDSolid-State Drive
A storage device that uses NAND flash memory with no moving parts, offering faster access times than traditional HDDs.
SSIDService Set Identifier
The name broadcasted by a wireless access point to identify a specific Wi-Fi network.
SSIDService Set Identifier
A case-sensitive string up to 32 characters long that identifies a specific wireless LAN that clients use to connect to the correct access point.
STIXStructured Threat Information eXpression
A standardized language for describing cyber threat intelligence in a structured, machine-readable format.
STPSpanning Tree Protocol
An IEEE 802.1D Layer 2 protocol that prevents switching loops by placing redundant switch ports in a blocking state.
TAXIITrusted Automated eXchange of Intelligence Information
A transport protocol used to share STIX-formatted cyber threat intelligence over HTTPS between organizations.
TCPTransmission Control Protocol
A connection-oriented Layer 4 protocol that provides reliable, ordered, and error-checked delivery of data between hosts.
TCP/IPTransmission Control Protocol/Internet Protocol
The foundational protocol suite used for communication across networks, providing addressing and reliable data delivery.
Thermal Paste
A thermally conductive compound applied between a CPU and heatsink to eliminate air gaps and improve heat transfer.
Threat Hunting
A proactive, analyst-driven process of searching for hidden or undetected threats within an environment.
Threat Intelligence
Analyzed information about current or potential threats used to inform and improve defensive security decisions.
TLSTransport Layer Security
A cryptographic protocol that provides encrypted, authenticated communication over a network, succeeding SSL.
TOTPTime-Based One-Time Password
A short-lived, one-time authentication code generated from a shared secret and the current timestamp, commonly used in MFA.
TTPsTactics, Techniques, and Procedures
Behavioral patterns and methods used by threat actors to plan and execute cyberattacks.
UDPUser Datagram Protocol
A connectionless Layer 4 protocol that transmits data without guaranteed delivery, ordering, or error checking, offering lower latency.
UEBAUser and Entity Behavior Analytics
A security capability that uses machine learning to detect anomalous behavior by users and devices compared to a baseline.
UEFIUnified Extensible Firmware Interface
Modern replacement for BIOS that supports larger disks, faster boot times, and a graphical firmware interface.
USBUniversal Serial Bus
A standard interface for connecting peripheral devices to computers, with versions ranging from 1.1 to 4.0 offering increasing data transfer speeds.
VGAVideo Graphics Array
An older analog video connector standard using a 15-pin DE-15 connector, now largely replaced by digital interfaces.
VLANVirtual Local Area Network
A logical segmentation of a physical network at Layer 2 that groups hosts independently of their physical location.
VPNVirtual Private Network
A technology that creates an encrypted tunnel over a public network to securely connect remote users or sites.
VPNVirtual Private Network
An encrypted tunnel over a public network that allows remote users or sites to securely access private network resources.
Vulnerability Scanning
An automated process that identifies known vulnerabilities, misconfigurations, and weaknesses in systems and applications.
VXLANVirtual Extensible LAN
A network virtualization encapsulation protocol (RFC 7348) that tunnels Layer 2 frames over a Layer 3 UDP network to extend VLANs across routed boundaries.
WAFWeb Application Firewall
A security appliance or service that filters and monitors HTTP/HTTPS traffic to protect web applications from attacks such as SQLi and XSS.
Zero Trust
A security model that requires continuous verification of every user and device, granting least-privilege access regardless of network location.